`(a) Definition- In this section, the term `greenhouse gas' means any of the following:

`(1) Water vapor.

`(2) Carbon dioxide.

`(3) Methane.

`(4) Nitrous oxide.

`(5) Sulfur hexafluoride.

`(6) Hydrofluorocarbons.

`(7) Perfluorocarbons.

`(8) Any other substance subject to, or proposed to be subject to, regulation, action, or consideration under this Act to address climate change.

`(b) Limitation on Agency Action-

`(1) LIMITATION-

`(A) IN GENERAL- The Administrator may not, under this Act, promulgate any regulation concerning, take action relating to, or take into consideration the emission of a greenhouse gas to address climate change.

`(B) AIR POLLUTANT DEFINITION- The definition of the term `air pollutant' in section 302(g) does not include a greenhouse gas. Notwithstanding the previous sentence, such definition may include a greenhouse gas for purposes of addressing concerns other than climate change.